I'm in the middle of my Wheel of Time re-read, and have come across something confusing. I seem to remember that initially, it was stated that the Three Oaths prevented an Aes Sedai from using the one power as a weapon, except against shadow-spawn and darkfriends, or in defence of her own life, that of her warder or another sister.
I think later on the series, the part about darkfriends seems to be omitted.
Now I'm reading The Dragon Reborn, and Nynaeve and Egwene are talking about forgetting about the Three Oaths, and striking down a member of the Black Ajah if they find one. But wouldn't this be OK, because Black Aes Sedai are darkfriends?
I will have to keep reading to remember, but I'm pretty sure there are other situations where Aes Sedai come face-to-face with this dilemma; but there shouldn't be a problem. What's going on?